This week, CommuniGate Systems announced the launch of its new patent-pending SIP Farm technology, as part of the CommuniGate Pro 5.0 Dynamic Cluster application server platform. The aim of the technology is to enable very large-scale VoIP deployments at the carrier/telco level.
Thom O’Connor, the company’s Director of Product Architecture, says the SIP Farm puts the CommuniGate Pro solution in a position to address the larger-than-Vonage market. “Vonage today is at about 1.2 million accounts, and most carriers are doing telephony for—the larger ones, at least—in the 20 to 50 million account range,” he says.
Supporting 20 to 50 million users is a significant challenge for any system, but O’Connor says CommuniGate Pro can now do it. To prove that it can, the company’s SIP Farm technology will go through benchmark testing at HP Labs from January 23 to March 6, 2006. “We also hope to have some large customer reference cases public by that timeframe,” he says.
Essentially, SIP Farm technology allows providers to scale system capacity and redundancy by adding additional nodes to the CommuniGate Pro 5.0 Dynamic Cluster as needed. “Each single server will be able to get over a million calls or busy hour call attempts per hour—but then by growing that with a cluster, you get that type of performance on each of those front-ends as the cluster grows,” O’Connor says.
A SIP Farm, then, is defined as a selected cluster of front-end servers. “All of the real-time traffic stays within that SIP Farm environment—and in the case that a server is lost or a new server is added, there is a reallocation of the way the sessions work in the cluster,” O’Connor says. “Even if a cluster member is lost, the SIP Farm will reallocate any active sessions that were on that lost system to other members of the SIP Farm.”
This is similar to what CommuniGate Pro already does with e-mail—but there are unique challenges, O’Connor says, in transferring the company’s established e-mail server clustering technology to VoIP. “What’s particularly tricky is doing all of that with UDP sessions, rather than traditional TCP sessions in the e-mail or messaging space,” he says. “It’s actually quite a significant challenge—and the reason for that is that UDP traffic, by its nature, is connectionless.”
That’s very different from TCP, where traffic is typically transmitted over infrequent and long-standing connections—and it’s the way the SIP Farm handles the challenges of UDP, O’Connor says, that’s patent-pending. “With UDP traffic, the analogy is you’re taking a million ping-pong balls and dropping them onto the cluster, and the cluster has to make sure that all those balls get to the right place immediately,” he says.
A SIP Farm cluster, O’Connor says, can also support broad geographic distribution. “You could have some front-end servers in Italy, some front-end servers in France, and the core of your cluster in another country—Germany, let’s say,” he says. “And even in that scenario, the systems will act as a single cluster.”
And in that scenario, O’Connor says most traffic will still remain local in order to optimize performance. “The clustering can take geographic spreading or distribution in order to keep that real-time traffic as close to the source and destination as possible,” he says.
It wasn’t long ago that CommuniGate first added SIP to its e-mail platform, and O’Connor says the response has been excellent so far. “We’re making some significant headway in the SIP and voice field—and it’s still fairly new to us,” he said.